Seeking plugin advice: Google maps + frontend posts

Hi folks
There isn’t a plugin out there to do what I need (as far as my search reveals), so I’m looking for a plugin to at least build upon as I cannot build plugins, and would rather exhaust every possibility before hiring as my budget is donations and currently that stands at $0.

What I need:
– Google map accessible to all.
– Members have permission to place markers (names of businesses) (has to be drag-and-drop for usability).
– Members have permission to add posts (via front end) associated with markers (reviews).

I only outlined what I need and want so you guys can direct me best and upon the possibility someone is capable of building such a plugin – it will be of use to many other people and my wife and I would be happy to sponsor a plugin author. If interest, let’s keep the forums clean by emailing privately: howard [at] evrn [dot] net.